Power washing/sanding AFTER brightening?

Hello! I have a 20+ year old deck in a home we just moved into in MN that looks like it has had very little care put into it. I've read up on everything here on the website I can, ordered TWP 100 and this should arrive today. I did a good deal of sanding/repair on the deck first, then used a cleaner and brightener and power-washed both off 2 days ago. After everything dried, the deck looks SO much better, but there are still some dark(er) spots, as well as some 'streaks' from the power washer (I'm a rookie with this apparently) . I used an orbital sander on the railings to remove any dark(er) spots and rough spots (as I saw that it is OK to sand after brightening on the forum)...

My question is, after 2 days of 'drying' having washed/brightened, now that I've noticed those dark(er) spots/power-wash streaks, if I were to re-power-wash those streaks out (figured out how to adjust the PSI now...was too strong before), will I need to brighten again prior to applying the TWP 100? Or will I be able to sand/or power-wash those spots/streaks out, let it dry, and move to the staining? Thanks for any help - this website is AMAZING by the way!